Railroad networks frequently include track switches which are used to direct trains between one of two possible destination tracks. A track switch includes a pair of switching rails, commonly referred to as switch points, which are linked to each other and are moveable between two end positions. This enables alignment of the switch points to allow continued movement on the current track when in one end position and allows movement to another stationary track when in the other end position.
A motorized switch machine is frequently used to move the switch points between the normal and reverse positions. With a conventional switch machine, several components used in moving the switch points such as connecting and operating rods and others are located in between and around adjoining railroad ties at a switch location. This is a disadvantage when performing tamping operations on a railroad track. In such operations, a tamping machine is used to pack or tamp track ballast, such as rocks, under the railroad ties and rails in order to provide a stable base for the railroad tracks and to reduce track maintenance and train vibrations. However, machine tamping cannot be performed around the area of a conventional switch machine since access to the track ballast is obstructed by the various switch machine components located between and around the railroad ties.
An alternate type of switch machine is an in-tie switch machine. In this type of switch machine, many of the various mechanisms and components used in moving the switch points, such as a switch machine, pawl lock, throw and detector rods and others are housed in a single compartment which also serves as a railroad tie. As a result, the areas between and around the railroad ties are cleared of these components and machine tamping operations in these areas may be performed. In-tie switch machines also increase the overall rigidity of a switch and help protect the switch machine components from damage thus reducing the number of switch failures.
Many in-tie switch machines include a rotatable hand crank mechanism which enables manual operation of the switch machine and a power cut off switch for turning off power to the switch machine motor. Such hand crank mechanisms, however, are small and require that an operator rotate the hand crank numerous times in order to move the switch points to a desired end position. In some cases, up to one hundred turns or more of the hand crank are required to move the switch points from one position to another, thus requiring a substantial amount of time and effort on the part of an operator. This is undesirable during normal train operation which requires that the switch points be quickly moved so that the train is not stopped for a significant amount of time. As such, hand cranks found on in-tie switch machines are suitable for performing installation and maintenance procedures associated with the switch machine but are not suitable for moving the switch points from one position to another during normal operations.
Further, the hand crank and cut off switch may be located in areas of an in-tie switch machine that provide limited access for the operator thus making operation of the hand crank and cut off switch difficult. The operator must also ensure that rotation of the hand crank is not hindered or blocked by track ballast, debris or other interfering item.
Therefore, there is a need for a mechanism for an in-tie switch machine that enables manual control of the switch machine and requires minimal time and effort to operate.